Tech: Lays down layers of powder and "prints" the design using a glue-like binder.

Advantages: Can do colour. Model structures are self-supporting via unused powder. "Green" parts can be infused with materials from glue to molten metal to strengthen. Unused powder can be reused.

Disadvantages: "Green" parts are fragile. Hollow parts will trap binder if no exit holes are designed in. Fabricated objects may be difficult or impossible to recycle back into machine inputs.

Fused Deposition Modeling (FDM)

Cost: Low

Tech: An extruder head deposits melted material (like plastic) or pastes to build up an object layer-by-layer.

Advantages: Cheap. Can be completely hollow and air-tight. Can be vestment-cast with molten metal. Simple machine design. For thermoplastic and similar materials, fabricated objects can be melted back down and reused.